1Department of Pharmacology, School of Medicine, Shahed University, Tehran, Iran
2School of Medicine, Shahed University, Tehran, Iran
3Department of Psychiatry, Shahid Beheshti University of Medical Sciences; Tehran, Iran
Background and Objective: The medicinal plant Origanum vulgare. subsp. vulgare in the Lamiaceae family has been widely used by Iranian people for the treatment of respiratory, gastrointestinal and neurologic disorders. The present study was carried out to evaluate possible anxiolytic effects of aqueous extract of O. vulgare leaves and the flowering branches in rats. Materials and Methods: Anxiolytic activity was assessed using the elevated plus-maze test. In addition, the possible sedative effect and muscle relaxant effect were evaluated using open field test and horizontal wire test, respectively. Single doses of O. vulgare extract(50, 100 and 200 m/kg) were administered intraperitoneally in male rats. Control rats were treated with an equal volume of saline, and the positive control rats with diazepam. Results: In the elevated plus-maze, O. vulgare extract(200 mg/kg) increased percent of time spent on open arms(p<0.001), and open arms entries(p<0.05), compared with saline group. In addition, the extract decreased locomotor activity in the open field test(p<0.05). However, unlike diazepam, the O. vulgare did not cause myorelaxant effect. Conclusion: These results suggest that the aqueous extract of O. vulgare leaves and flowers has anxiolytic effect and may also have potential sedative effects.